Chaoshou ("folded arms") is the Sichuanese dialect name for the dumpling that the Cantonese call wonton ("swallow a cloud"). The Sichunaese take on the traditional boiled-wontons-in-soup is called long chaoshou (dragon wontons). There are many other variants, including suanla chaoshou (hot-and-sour boiled wontons). Here are two variants of that dish.
The first is allegedly the version that was the signature appetizer at Mary Chung's restaurant in Cambridge MA near the MIT campus. It matches my recollection of the dish.
Ingredients
raw fresh or frozenwontons (preferable leaf fold), 5 or more per person (I'm greedy and eat 15 or more)
raw mung bean sprouts
Sauce
2 TBS dark soy sauce
4 TBS water (I used chicken broth)
1 tsp vinegar (I used Zhenjiang [aka Chinkiang] black vinegar0
1 TBS minced garlic
1/2 TBS minced ginger
1 tsp hot oil (with or without the hot oil paste)
Mix everything together and let it sit for a day before using, in order to marry the flavors.
Make the wontons according to your favorite recipe. I use the "leaf" wonton fold. Allow at least 5 wontons per person (I'm greedy and eat 15 or more at a sitting).
Procedure
[1] Add the wontons to a large pot of boiling water. When the water starts to return to the boil, add 1/2 cup cold water and wait for it to return to the boil. Add another 1/2 cup cold water. The wontons are done when they float. If not serving immediately rinse them with cold water to stop the cooking process.
[2] To serve, place a mess of raw bean sprouts on each serving place, top with the wontons, and pour a tablespoon (or more, depending on how many wontons per serving) of the sauce over the top.
Here is Fuchsia Dunlop's recipe for suanla chaoshou:
40 or so fresh or frozen wontons (preferably leaf fold)
Sauce (per serving)
1/2 tsp light soy sauce
2 tsp Zhenjiang (aka Chinkiang) black vinegar
1/2 tsp melted lard
1/2 tsp sesame oil
1 TBS scallion greens, thinly sliced crosswise
7 TBS piping hot chicken stock
a couple of good pinches ground white pepper
Procedure
[1] Have the piping hot chicken stock at the ready.
[2] Boil the wontons as per the Mary Chung's recipe, above, but do not rinse them under cold water (you will be serving them immediately).
[3] Mix the sauce and put one portion in each serving bowl. Add the wontons, mix up to coat them thoroughly, and serve immediately.
NOTE: I don't bother with the "add 1/2 cup cold water and return to boil" steps when I boil wontons.
-Paul W.